This invention relates to an apparatus and a method capable of manufacturing a single welded panel by welding abutted edges of a plurality of material panels and, more particularly, to an apparatus and a method capable of manufacturing a plurality of different types of welded panels.
When an automotive door panel is produced with a press from a single material, a portion thereof having a considerably large area corresponding to a window is wasted, which is undesired from the standpoint of the effective utilization of the material. Accordingly, an apparatus for manufacturing a welded panel 50C, as shown in FIG. 9, has been developed. In this apparatus, a plurality of material panels 20C, 22C, 24C and 26C are set in an abutting relation to one another using a welder member 30C and are welded together by irradiating their abutted edges WL with a welding beam (for instance a laser beam LZ). In this way, a single welded panel 50C is produced. This apparatus is disclosed in Japanese Laid-Open Patent Publication No. 59-220229.
FIG. 10 shows an apparatus for welded panel manufacture, which realizes this technique. FIG. 9 shows an example of manufacturing a welded panel 50C of type C, while FIG. 10 shows an example of manufacturing a welded panel D of type D.
In FIG. 10, designated at I is a prearranging section, in which stacks of material panels 20D, 22D, 24D, 26D and 28D are set on a pallet 18D, which is moved along guide rails 13 and 15 to a material input section II. In the material input section II, the stacks of material panels 20D, 22D, 24D, 26D and 28D are fed one by one from the uppermost ones to a welder member 30D by a material feeder (not shown). In the welder member 30D, the individual material panels in a set are positioned such that their edges are abutted as in the example shown in FIG. 9. Designated at III is a welding section. In this section, the abutted edges WL as shown in FIG. 9 are irradiated with a laser beam coupled from a laser oscillator 42 via a torch 46. As a result, the material panels 20D, 22D, 24D, 26D and 28D in the set are welded together to obtain a single welded panel 50D. The welded panel 50D thus obtained is fed by a feeder 53 to a grinding section IV. In the grinding section IV, the welding bead is ground away with a rotating grindstone. Designated at V is a punching section, in which the corners (designated at X in FIG. 9) between adjacent abutted material panels are finished to be smooth by a punching process. Designated at VI are a stacking section, in which finished welded panels 50D are stacked on a base 86. When a predetermined number of finished welded panels are stacked, they are fed to the next step by moving the base 86 supporting them along guide rails 88 and 90.
When a single welded panel is produced by welding together the individual material panels in one set, the wasted material can be extremely reduced. However, the manufacture of one type of welded panel requires an exclusive manufacturing system, and it is difficult to provide a manufacturing system, which can manufacture a number of different types of welded panels; for instance, it is difficult for the apparatus shown in FIG. 10 to manufacture welded panels of types C and D.
In order to be able to manufacture a plurality of different types of welded panels with the apparatus shown in FIG. 10, it may be thought to permit movement of a positioning stopper for the welder member 30 and also positioning cylinders for the material panels such as to conform to the intended type of welded panel. However, for the irradiation of the abutted edges with a welding beam it is necessary for the positions of the abutted edges to have an accuracy of about 0.1 mm. Therefore, with the system, in which the position of the stopper for the welder member 30 is variable, it is impossible to ensure satisfactory welding.
As another proposal, it may be thought to prepare welder members 30 for different types of welded panels and provide means for guiding a welder member in a direction perpendicular to the direction of feed of the work so as to permit replacement of the welder member with desired ones. However, as shown in FIG. 10, the laser oscillator 42, the laser beam guide path 44, the mechanism for scanning the laser beam torch 46, etc. are disposed in a complicated manner along the edge of the welding section III requiring the welder member 30, and therefore it is extremely difficult to dispose the replacement means for the welder member 30 so as not to interfere with these components. Particularly, where a plurality of laser beam torches 46 are disposed (two torches 46B and 46F being disposed in the example of FIG. 10) to effect welding of a plurality of abutment edges at a time so as to improve the welding speed, the structure of the welding section III is correspondingly complicated, and it is extremely difficult to provide the replacement means for the welder member 30 so as to be free from the interference. Particularly, where laser oscillators are disposed on the opposite sides of the line, it is almost impossible to secure the welder member replacement paths.
For the above reasons, it is difficult to realize the idea of replacing the welder member 30.